"I'm curious why you say you're 'very much' in the WWW camp but you don't use it on your own site." would not have the same tendency to register as an attack.
When you see something that you might think is hostile, it's often more productive to give them the benefit of the doubt and presume that they intended good faith but have different conversational norms from you. In the best case, they meant well, and everything proceeds nicely. In the slightly worse case, they didn't mean well, but you've helped de-escalate, and things are back on track for a nice discussion. In the worst case, they get more blatant in their attacks, and at least you'll find out that productive discussion wasn't possible anyway. Not much downside, and lots of upside, in my experience.